So after several months of searching I got lucky on eBay last week and happened upon an original cone K120 about 20 minutes after it was listed. Score! Anyway, the speaker arrived today and I just got through putting it through its paces. It's different than the E120 I've been playing through, and I'm still trying to figure out the adjustments I'll need to make to get the most out of it. I'm curious if my brief observations are consistent with other's experiences, or if I'm off in the weeds?

As an aside, I'm using a SSP 1X12 cab and my home/practice amp, a Mesa TA-15 that's been re-tubed with JJ's: an ECC803S in the V1 (clean) position and JJ ECC83S in the V2, V3, and V4 positions, and JJ EL84s in the power tube positions. The ECC803S is a lower gain version of the ECC83S, so the TA-15's first channel is fairly clean, warm, and "full". It isn't as sweet sounding as my SMS CTP & MC50, but it's a lot smaller and easier to live with in the house, and as I just got it I haven't had the chance to play it with the bigger setup yet.

I had the Mesa dialed in pretty well for the E120, but after changing speakers and plugging back in, I was immediately struck by how much more efficient -- and brighter! -- the K120 is than the E120. Settings that permitted me to get a nice tone from the E120 at bedroom-to-loud-bedroom levels made the K120 sound rather shrill. Some of this may be that the K120 is exposing more of the true tone of this particular Mesa (and these JJ tubes), but it was really surprising to me just how radically different these two speakers sounded. I'm sure the warmth is in the speaker, but I'm still figuring out how to get it out.

Is this a "typical" experience with a K120? I was expecting a sweeter, less shrill sounding speaker, but as I said, I think some of what I'm hearing is just the Mesa being very accurate/sterile, and perhaps the JJ's being a little harsh? I guess I'll know more on the weekend when I'll have the time to play through the SMS, but I'd enjoy hearing from others who have played their rig with both speakers, and what adjustments, if any, you needed to make?

I dropped my gain down a bit and lowered the power setting on the amp down to 5 watts, and at lower volumes this speaker sounds fantastic -- really transparent and clear without being sterile, or in other words, "just what I was hoping for." I was playing it pretty loud before, and I must have had some setting(s) that just didn't agree with the speaker at that volume. Lesson learned: despite outward appearances, the K120 is different and behaves differently than the E120, and I'll need to make some adjustments the next time I crank it up.

That...is not what I would've expected. I have my E in a cab with a K. I bought the E on a screaming deal ($65 on a languishing Ebay auction ((or something like that))). It has been my experience that the K is the "Warmer" speaker...by far.

That Mesa is a whole bunch of tone sculpting. I find my SMS very plug & play. It's great for that reason, and really that makes sense in a rack rig. The little Mesa is a tone factory. My son & I were jamming last night. He was playing the Mesa for the first time, and he ended up taking it home for "Furthur Study." I was playing through a '68 Deluxe (D120), with a Sarno suggested tone stack. Whenever that TA-15 comes out, I remember why I bought it. That thing is a fantastic amplifier.

I was gonna say I think your speaker has issues, Glad you got it singing properly. My K120 is a lot like my E120 but a tad warmer, but I haven't stressed it out yet to hear it that way.

BUT! I have to admit that my fresh coned E120 next to my commonwealths sounded almost identical. I think the old original cones of the E120's add a little brittle and brightness to the tone. The recone E has a tight bass that is present, mids galore and a high presence that is sparkly, nothing brittle. That's just like my commonwealths when I got them. My E120 with the 30 year old cone seemed "dull-er" but brighter overall. Actually I described the commonwealths having a bass response that was a little different & more present. Well a fresh e120 has comparable bass response too now much like the commonwealths, its a tight bass not slopy. So I guess my commonwealths suffered from sounding better, more responsive, than my vintage original cone E120.And that difference made me wonder if they didn't sound like E120's. I know better now.

What I found out also, is how similar they really are in construction. I am sure the beyma's are just like that too. 4" voice coil, big ceramic magnet, paper cone that weighs roughly the same, vented nomex former, edgewound aluminum voice coil and dust cap. I guess I had to compare fresh cones to fresh cones ! I have to say that my speaker search is over, except for one more K120 magnet to cone up, and I will be finished with speakers.

I am sure all the clones differ some, but its hair splitting even more now that I have an actual brand new e120 to compare it to. I moved my K120 to my Deluxe and it sings like Whitney Houston. it has an original cone and seems "dull" compared to my newer speakers, but it still sounds awesome ad Im stoked. I would love to hear about mixing a K120 into an E120 cab. Right now Im kill myself moving a birch cab and 2 E120's. I am putting my commonwealths into some floor wedges to give me a loud ass monitor system like Jerry too! Happy JBL JAmming!!!

Last edited by JonnyBoy on Sun Jul 01, 2012 8:22 pm, edited 1 time in total.

Sounds very cool, JonnyBoy. By the way, did you do your own recones or have someone do them? Someone you can recommend? I have an E120 that I'd like to get reconed, and I haven't found a shop yet.

Having spent a little more time with the K120, I have to say I am really liking it a lot. For me, the big difference is how much more expressive it is at low volume levels. I play a lot at night after the kids are asleep, and I can get so much more sound out of the K120 at those volumes, it's like night and day. I think that was part of my original problem -- I had TA-15 dialed in for getting good tones from the E120 at bedroom levels, and those settings were way off for the K120. It caught me off guard even though I knew the speakers were going to behave differently.

I bought a K120 off EBay but had to get it reconed because of damage during shipping, so I sent it to Weber. During that time I borrowed the other guitarist in our band's Weber neomag. I run a silverface '73 Twin (with 2 tubes pulled out so it's 50 watts) into a 1x12 SSP cab. I liked the neomag okay, it had that nice ringy high end, especially when I was able to open up the Twin a good bit (all the way up to 3 1/2!). But when I got the K120 back from Weber, it had all that and then some. All those highs were there, but it had a lot more low end to balance it out. And it just gets better the more you push it. The other guitarist I mentioned (who does the Weir parts in the band) was running an E120 along with a Gauss in his Mesa rig (Studio Pre into a 2-90 I think), and recently switched to 2 Weber reconed K120s and is way happier as well. My feeling is with the JBLs they can sound absolutely awesome, but they need to be pushed to somewhere close to their limits. It seems like Jerry maybe switched from k120s to E120s because he was blowing the Ks, but he was pushing the Es so hard they sounded just as good. I wonder if D120s might sound better than either in a lower wattage situation. I use a 15watt Super Champ XC into a JBL D123 (rated at 25 watts I think) at home, and with the Super Champ set to sound like a blackface Twin, it sounds really good. It's still loud as hell. I think the trick with the JBLs is to pick the right ones for the power of the amp you're running into them.

redeyedjim wrote:Sounds very cool, JonnyBoy. By the way, did you do your own recones or have someone do them? Someone you can recommend? I have an E120 that I'd like to get reconed, and I haven't found a shop yet.

The drummer in my band was (and still is but not professionally) the trained JBL recone specialist in Jackson Ms. He went to a 2 week training seminar and reconed all the JBL's in our area back in the day. He did a smack down job and coned it in literally 5 minutes. I had it all cleaned up and ready to glue tho. Its really easy, or at least he made it seem so. He plopped it on a "Lazy Suzie" and spun it around glued it with the glue in a circle, then plopped the kit in, shimmed it, set it to the side to dry all within a minutes time. Then he did the dust cap the next day. Gave it to me later that afternoon. Sounds awesome too!! I had the cones and materials. He can't get them anymore. I would go to weber or the like.